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Spatially Varying Image Based Lighting by Light Probe Sequences, Capture, Processing and RenderingUnger, Jonas, Gustavson, Stefan, Ynnerman, Anders January 2007 (has links)
We present a novel technique for capturing spatially or temporally resolved light probe sequences, and using them for image based lighting. For this purpose we have designed and built a real-time light probe, a catadioptric imaging system that can capture the full dynamic range of the lighting incident at each point in space at video frame rates, while being moved through a scene. The real-time light probe uses a digital imaging system which we have programmed to capture high quality, photometrically accurate color images of 512×512 pixels with a dynamic range of 10000000:1 at 25 frames per second. By tracking the position and orientation of the light probe, it is possible to transform each light probe into a common frame of reference in world coordinates, and map each point and direction in space along the path of motion to a particular frame and pixel in the light probe sequence. We demonstrate our technique by rendering synthetic objects illuminated by complex real world lighting, first by using traditional image based lighting methods and temporally varying light probe illumination, and second an extension to handle spatially varying lighting conditions across large objects and object motion along an extended path.
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Synthesis, Characterization and Application of Luminescent Quantum Dots and Microcrystalline PhosphorsKang, Zhitao 20 November 2006 (has links)
Si QDs embedded in SiOx or SiNx thin films, which could emit light in the entire visible range from 440 nm to 840 nm by controlling their size and/or their matrix, were synthesized by evaporation or plasma enhanced chemical vapor deposition techniques. Various shades of white could be obtained from multi-layered SiNx film structures by controlling the size of Si QDs and layer thickness. It was shown that the combination of these films can produce white emission spectra with superior color rendering properties compared to conventional fluorescent tubes. Such Si-based QDs can be used as down-converting phosphors to coat a blue/UV LED to generate white light, providing a less expensive fabrication process to obtain advanced solid state lighting devices. As a supplement, free CdTe QDs with emission colors spanning 520~700 nm and quantum efficiency up to 54%, were synthesized using a colloidal chemical method for white LED applications. White PL and a range of emission colors were obtained from mixed CdTe QD samples excited by a 420 nm blue LED. Another part of this research was to develop a new x-ray powder phosphor, ZnTe:O, for biological imaging applications used in CCD-based synchrotron x-ray detectors. A unique dry synthesis process, including gaseous dry doping and etching procedures, was developed to synthesize ZnTe:O phosphors. The excellent x-ray luminescence results of oxygen doped ZnTe, including high efficiency, high resolution, fast decay, low afterglow and an improved spectral match to the CCD detector, indicated that ZnTe:O is a promising phosphor candidate for x-ray imaging applications.
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The Study of Organic Light-Emitting Devices in Application of Display and LightingLin, Yi-Hong 23 July 2012 (has links)
OLEDs for display and lighting applications were studied. Both RGB and color filter technologies were discussed in the display section; meanwhile, RGB white light and tendem white light were discussed in the lighting section.
A high performance RGB white display using 1,3,5-tri(1-pyrenyl) benzene (TPB3), C545T (166000 cd/m2) and DCJTB (70600 cd/m2) has been prepared with a 53.3% color gamut.
For the color display using PLED technology, a glycerol modified PEDOT (G-PEDOT) is used as buffer layer material. Luminance of the white PLED display increases significantly from 11580 cd/m2 to 16040 cd/m2. A 54.5% color gamut color display is prepared using the white PLED device with a color filter.
RGB white device with maximum luminance of 55800 cd/m2, maximum luminance efficiency of 4.55 cd/A, maximum power efficiency of 3.85 lm/W, and CIE coordinate of (0.33, 0.32) is prepared with a device structure of ITO(1300A)/NPB(500A)/TPB3(200A)/DPVBi¡G2% DSB(150A)/Alq3¡G2% DCJTB (150A)/ Alq3(350A)/LiF(8A)/Al(2000A). A high performance single emission layer white OLED device is also prepared. This single-layer device achieves a maximum luminance of 95200 cd/m2, maximum luminance efficiency of 5.9 cd/A, maximum power efficiency of 4.06 lm/W, and CIE coordinate of (0.34, 0.39) with a device structure of ITO(1300A)/NPB(650A)/TPB3:6% DSB:0.6% DCJTB(400A)/Alq3(300A)/LiF(8A)/Al(2000A).
Optimization of a tandem OLED device is conducted using a Alq3¡GLi/ HAT-CN interlayer. It is found that turn-on voltage is reduced effectively using the Alq3¡GLi/ HAT-CN interlayer at 20 mA/cm2. Power efficiency is increased to 2.24 lm/W, and maximum luminance of 71790 cd/m2 is achieved with a CIE coordinate of (0.30, 0.39).
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Pixel Noir: a style for cinematic computer-generated lightingHan, Lei 12 April 2006 (has links)
This thesis provides an example of creating a special cinematic style of Film Noir
in computer-generated animation. The thesis is designed as a discussion of how a
unique lighting style in computer graphics can be used to enhance visual storytelling
for cinematic purposes. It provides digital filmmakers a beginning guide to deal with
various lighting situations, and with cinematic lighting in 3D production.
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A web-based approach to image-based lighting using high dynamic range images and QuickTime object virtual realityCuellar, Tamara Melissa 10 October 2008 (has links)
This thesis presents a web-based approach to lighting three-dimensional
geometry in a virtual scene. The use of High Dynamic Range (HDR) images for the
lighting model makes it possible to convey a greater sense of photorealism than can be
provided with a conventional computer generated three-point lighting setup. The use of
QuickTime ™ Object Virtual Reality to display the three-dimensional geometry offers a
sophisticated user experience and a convenient method for viewing virtual objects over
the web. With this work, I generate original High Dynamic Range images for the
purpose of image-based lighting and use the QuickTime ™ Object Virtual Reality
framework to creatively alter the paradigm of object VR for use in object lighting. The
result is two scenarios: one that allows for the virtual manipulation of an object within a
lit scene, and another with the virtual manipulation of light around a static object. Future
work might include the animation of High Dynamic Range image-based lighting, with
emphasis on such features as depth of field and glare generation.
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Functional Properties of Concrete Roads - Development of an Optimisation Model and Studies on Road Lighting Design and Joint PerformanceLöfsjögård, Malin January 2003 (has links)
<p>The roads constitute a major part of the nationsinfrastructure. For the society and the individuals it isimportant with a well functioning road network. To sustain theimpact from traffic intensity and heavy loads durable pavementsare demanded. Concrete pavements for roads with high trafficintensity and heavy loads are common in the USA and in severalEuropean countries. In Sweden, less than 1 % of the roadnetwork consists of concrete roads.</p><p>The research about concrete road pavements has been focusingon development of design methods and studies of surfaceproperties like friction, longitudinal evenness, wearresistance and noise. To increase the knowledge and use ofconcrete roads there is a need to optimise the differentfunctional properties with regard to each other and to socialfactors.</p><p>The objective of this doctoral thesis is to survey, analyseand quantify relationships between functional properties ofconcrete roads and social factors such as environmental impact,traffic and user safety, riding comfort and economicconsiderations (costs). The goal is to develop a model that canbe used as an instrument for optimising the concrete roaddesign.</p><p>This thesis describes a thorough literature investigation,special studies on road lighting design of concrete pavements,laboratory investigations about saw-cutting times for jointsand bonding properties of dowels and development of anoptimisation model. The literature investigation has resultedin compiled knowledge on functional properties of concreteroads and their relationships with social factors. A compiledanalysis has also been performed from follow-ups of the fourconcrete roads constructed in Sweden in the 1990s. From thespecial study on road lighting design, proposals are made forusing new values for brightness and specularity and changingthe classification of wet concrete pavements. Theinvestigations of joint performance have given recommendationsfor the earliest saw-cutting time for joints in concrete roads.An optimisation model is proposed, and presently parts of themodel can be used for economic comparisons between differentalternatives.</p><p>The proposed model needs further research regardingvaluation of the relationships before the model can be used asa total model. Other areas interesting for further researchare: road lighting design and especially wet pavements, upperbound of sawcutting time for joints and further analysis ofdowel performance.</p>
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Resonant power MOSFET drivers for LED lighting /Tuladhar, Looja R. January 2009 (has links)
Thesis (M.S.)--Youngstown State University, 2009. / Includes bibliographical references (leaves 44-45). Also available via the World Wide Web in PDF format.
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Ljusföroreningar i stadsmiljö : Hur kan ljusföroreningar förebyggas vid nybyggnation?Sjöling, Jakob January 2015 (has links)
Light pollution in urban areas - How to prevent light pollution at construction Jakob Sjöling Light pollution is a relatively new but rapidly growing form of pollution. Society's increasing demand for light coupled with the pace at which lighting technology evolves is accelerating that growth. The purpose of this study was to analyse how the construction industry plan and design outdoor lighting when erecting new buildings, specifically with regards to the issue of light pollution. It also investigated how local authorities work with these issues during urban planning. In both cases special interest was placed in ways to improve the planning and use of outdoor lighting in order to minimize light pollution. To this end a series of interviews were held with people in the construction industry who are involved in the planning of lighting. Interviews were also held with local officials who manages issues of lighting and the environment within the municipality of Kungsbacka, Sweden. The interviews showed that people who work with these issues were well aware that poorly planned lighting can cause glare and disturbances. They were, however, almost totally unaware of the severe danger that light at night poses to both human health and environmental stability. To remedy this, information about the risks posed by night-time lighting must be spread from the scientific community to entrepreneurs and local officials who work with lighting. There are also several areas where changes in routines can help to avoid many of the potential pitfalls threatening to cause an, otherwise good, lighting plan to fail in regards to light pollution.
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Discovering signs: a study of cantilever neonsignage as a post-war urban vernacular heritage of Hong KongCheng Chong-kuen, Elson., 鄭昶權. January 2009 (has links)
The emergence of Cantilever Neon Signage has accompanied with the
grown-up of Hong Kong urban development after World War II. This
enormous steel frame covered with bent neon lights has been erected
onto the external wall over the streets of Hong Kong city in the past few
decades. Its image has been firmly imprinted on every citizen’s memory
by its multi-colored and eye-catching gesture. The signal itself embodies
part of the social and urban development history of Hong Kong. However,
its role in this city has been fading out following with the city’s renewal
and advancement in information technology. It is afraid that the
Cantilever Neon Signage will end up with a calamitous fate one day as
all of them will be eradicated from our city. Throughout this dissertation,
we tried to unveil some hidden stories behind this mysterious mask by
unravelling the development history and exploring this fading industry in
person throughout face-face site visits. The results were astonishing as
less people would commit to this handicraft driven industry and it
coupled with austere statutory controls which have inevitably halted
further potential successors to enter into the industry. / published_or_final_version / Conservation / Master / Master of Science in Conservation
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An Integrated Scalable Lighting Simulation ToolHuang, Yi Chun 01 July 2011 (has links)
Lighting simulation contribute readily to the synthesis of high performance lighting designs. Unfortunately there exist several issues impeding the pervasive use of lighting simulation, including: Most of the time in preparing lighting simulations is spent towards the input of existing but non-interoperable information between different tools. Lighting simulation tools do not complement integrated building design processes where the design solution is progressively developed in multiple disciplines concurrently; lighting simulation tools require design information (attributes) that may not yet be defined, and is non-interoperable with other tools. . Disparate tools with vastly different technical approaches available for different stages of the building design process do not allow consistent or meaningful performance comparisons between design versions, and similarly makes design performance progress tracking between design versions difficult. Lighting simulation tools provide radiance and irradiance values as simulation results, and much time and manual effort is required to process these results into operative information, information that is directly applicable in making design decisions. Lighting simulation tools employ outdated rendering techniques that are inadequate in evaluating highly-reflected irradiance, a typical feature in high performance building designs.
While there remain other shortcomings in lighting simulation tools as identified by contemporary research3, the issues above relate closely to the overall effort and time-cost factors attributed to using simulation tools, which has been consistently identified as obstacles towards using simulation tools. This research seeks to reduce the effort and time-cost required to conduct lighting simulation by addressing the issues above. Case studies of actual design scenarios are used to establish quantitatively the effort and time costs baselines for comparison.
The effort and time reduction goal is structured as the following objectives in a new lighting design support tool: Reduce the time and effort to set up and conduct lighting simulation by using interoperable information (building information models) from design modeling tools. Complement integrated design processes by supporting design models of varying completeness5, in a format that is interoperable with tools from other disciplines in the design team. All information, including assumptions, must be consistent across all disciplines. Provide ability to use performance metrics and consistent technical approaches throughout design stages, regardless of completeness of design model. Provide operative information with minimum user effort. Implement a first principle-based rendering technique that handles high performance building designs well, and produce simulation results within reasonable time constraints.
By meeting these objectives, the new lighting design tool is able to automate much of the previously manual, time-consuming, and disparate efforts in lighting simulation, thus reducing the effort and time-cost. By sharing interoperable information with other tools across the design team, the new lighting design tool is integrated. The new tool is also scalable in being able to support models of varying completeness throughout all design stages.
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